Enforce quoting style in Travis. (#4589)

python/ray/autoscaler/autoscaler.py

@@ -746,7 +746,7 @@ def hash_runtime_conf(file_mounts, extra_objs):
     def add_content_hashes(path):
         def add_hash_of_file(fpath):
             with open(fpath, "rb") as f:
-                for chunk in iter(lambda: f.read(2**20), b''):
+                for chunk in iter(lambda: f.read(2**20), b""):
                     hasher.update(chunk)
 
         path = os.path.expanduser(path)

python/ray/autoscaler/aws/config.py

@@ -173,7 +173,7 @@ def _configure_subnet(config):
             "on instance launch unless you set 'use_internal_ips': True in "
             "the 'provider' config.")
     if "availability_zone" in config["provider"]:
-        azs = config["provider"]["availability_zone"].split(',')
+        azs = config["provider"]["availability_zone"].split(",")
         subnets = [s for s in subnets if s.availability_zone in azs]
         if not subnets:
             raise Exception(
@@ -315,11 +315,11 @@ def _get_key(key_name, config):
 
 
 def _client(name, config):
-    boto_config = Config(retries={'max_attempts': BOTO_MAX_RETRIES})
+    boto_config = Config(retries={"max_attempts": BOTO_MAX_RETRIES})
     return boto3.client(name, config["provider"]["region"], config=boto_config)
 
 
 def _resource(name, config):
-    boto_config = Config(retries={'max_attempts': BOTO_MAX_RETRIES})
+    boto_config = Config(retries={"max_attempts": BOTO_MAX_RETRIES})
     return boto3.resource(
         name, config["provider"]["region"], config=boto_config)

python/ray/autoscaler/aws/node_provider.py

@@ -36,7 +36,7 @@ def from_aws_format(tags):
 class AWSNodeProvider(NodeProvider):
     def __init__(self, provider_config, cluster_name):
         NodeProvider.__init__(self, provider_config, cluster_name)
-        config = Config(retries={'max_attempts': BOTO_MAX_RETRIES})
+        config = Config(retries={"max_attempts": BOTO_MAX_RETRIES})
         self.ec2 = boto3.resource(
             "ec2", region_name=provider_config["region"], config=config)